V4L2VideoDecodeAccelerator: support external buffer import

media/gpu/v4l2_image_processor.h

Index: media/gpu/v4l2_image_processor.h
diff --git a/media/gpu/v4l2_image_processor.h b/media/gpu/v4l2_image_processor.h
index 3e456b9c32158683e323854eaf268fae5f0485f2..61bf1055a006713ad7beee77cb3b1c8ca13b682d 100644
--- a/media/gpu/v4l2_image_processor.h
+++ b/media/gpu/v4l2_image_processor.h
@@ -41,6 +41,7 @@ class MEDIA_GPU_EXPORT V4L2ImageProcessor {
   bool Initialize(VideoPixelFormat input_format,
                   VideoPixelFormat output_format,
                   v4l2_memory input_memory_type,
+                  v4l2_memory output_memory_type,
                   gfx::Size input_visible_size,
                   gfx::Size input_allocated_size,
                   gfx::Size output_visible_size,
@@ -84,9 +85,12 @@ class MEDIA_GPU_EXPORT V4L2ImageProcessor {
   // Called by client to process |frame|. The resulting processed frame will be
   // stored in |output_buffer_index| output buffer and notified via |cb|. The
   // processor will drop all its references to |frame| after it finishes
-  // accessing it.
+  // accessing it. If |output_memory_type_| is V4L2_MEMORY_DMABUF, the caller
+  // should pass non-empty |output_dmabuf_fds| and the processed frame will be
+  // stored in those buffers.
   void Process(const scoped_refptr<VideoFrame>& frame,
                int output_buffer_index,
+               std::vector<base::ScopedFD> output_dmabuf_fds,
                const FrameReadyCB& cb);
 
   // Stop all processing and clean up. After this method returns no more
@@ -106,8 +110,10 @@ class MEDIA_GPU_EXPORT V4L2ImageProcessor {
   // Record for output buffers.
   struct OutputRecord {
     OutputRecord();
+    OutputRecord(OutputRecord&&) = default;
     ~OutputRecord();
     bool at_device;
+    std::vector<base::ScopedFD> dmabuf_fds;
   };
 
   // Job record. Jobs are processed in a FIFO order. This is separate from
@@ -119,6 +125,7 @@ class MEDIA_GPU_EXPORT V4L2ImageProcessor {
     ~JobRecord();
     scoped_refptr<VideoFrame> frame;
     int output_buffer_index;
+    std::vector<base::ScopedFD> output_dmabuf_fds;
     FrameReadyCB ready_cb;
   };
 
@@ -161,6 +168,7 @@ class MEDIA_GPU_EXPORT V4L2ImageProcessor {
   VideoPixelFormat input_format_;
   VideoPixelFormat output_format_;
   v4l2_memory input_memory_type_;
+  v4l2_memory output_memory_type_;
   uint32_t input_format_fourcc_;
   uint32_t output_format_fourcc_;